Pseudomonas aeruginosa surgical site infection is a serious infection with significant patientrnmortality and health-care costs. The emergence of multidrug resistant strains ofrnPseudomonas aeruginosa has complicated treatment decisions and leads to treatmentrnfailures. In Ethiopia, few studies were conducted and even those studies were done generallyrnon gram-negative bacteria not specifically on Pseudomonas aeruginosa from surgical sitesrndespite the fact that P.aeruginosa is becoming serious cause of opportunistic infection inrnimmunocompromised and hospitalized post operative patients. Nevertheless, the relationshiprnbetween appropriate antimicrobial treatment and clinical outcome is not well established inrnTikur Anbessa hospital. This is a prospective study of surgical wound infection on surgicalrnpatients operated from April to July 2006 in Tikur Anbessa hospital. A total of 173 patientsrnwere enrolled and clinical samples collected for analysis. Demographic data and laboratoryrnanalysis test on the occurrence of Pseudomonas aeruginosa wound infection rate andrnantimicrobial susceptibility patterns has been conducted in the first 30 days postoperatively.rnAmong the patients, there were 97(56%) male patients and 76(44%) female patients. Thernmean age of the patients was 37.3(range: 1-80 years).rnThe infection rate was 10.3%, 13.6%, 22.7% and 36.8% for clean, clean-contaminated,rncontaminated and dirty wounds respectively. The rate of surgical site infection was 17.9%rnwith Pseudomonas aeruginosa being 14.4% of all the isolates. On comparing infectedrnpatients (n=31) with non-infected patients (n=142), there was no significant difference in thernfrequency of infection by sex (p= 0.11). Pseudomonas aeruginosa was the third dominantrnisolates following Staphylococcus aureus and coagulase negative Staphylococcirnrespectively. The prevalence of drug resistance to Amikacin, Azeotronam, Ceftriaxone,rnCeftazidime, Chloroamphenicol, Ciprofloxacine, Gentamicin, Imipene, Piperacillin,rnTetracycline and Trimethoprim-Sulfamethoxazole was evaluated.rnThe minimum resistance rate was 25% for Amikacin and Imipenem and the highestrnresistance rate obtained was for Chloroamphenicol which was 100%. 87% of the isolates ofrnP.aeruginosa were multidrug resistant. The outcome of this research emphasizes the use ofrnfirst line drug therapy rather than random prescription of antibiotics with out susceptibilityrn9rntesting. This will aggravate the ever increasing resistance not only to Pseudomonasrnaeruginosa but also to other microorganisms. Policies governing the use of antimicrobials inrnmany institutions are lacking. Such policies must be implemented in order to limit the spreadrnof resistance.